Wide Area Telephone Service

Wide Area Telephone Service (WATS) was a flat-rate long-distance service for customer dial-type telecommunications in the service areas of the North American Numbering Plan (NANP).

The service was between a given customer phone (also known as a "station") and stations within specified geographic rate areas, employing a single telephone line between the customer location and the serving central office. Each access line could be arranged for outward (OUT-WATS) or inward (IN-WATS) service, or both.

WATS was introduced by the Bell System in 1961 as a long-distance flat-rate plan by which a business could obtain a special line with an included number of hours ('measured time' or 'full-time') of long-distance calling to a specified area. These lines were most often connected to private branch exchanges in large businesses. WATS lines were the basis for the first direct-dial toll-free 1-800-numbers (intrastate in 1966, interstate in 1967); by 1976, WATS brought AT&T Corporation a billion dollars in annual revenue ($5.53 billion in 2024 dollars)

For outbound calls, the 1984 AT&T divestiture brought multiple competitors offering similar services using standard business telephone lines; the special WATS line was ultimately supplanted by other flat-rate offerings. The requirement that an inbound toll-free number terminate at a special WATS line or fixed-rate service was also rendered obsolete by the 1980s due to intelligent network capability and technological improvement in the 800-service. A toll-free number may now terminate at a T-carrier line, at any standard local telephone number or at one of multiple destinations based on time of day, call origin, cost or other factors.